岩石蠕变模型的比较和修正

对三种岩石在不同的应力下进行了蠕变实验,对蠕变实验曲线用粘弹模型进行了模型参数的反演,结果认为标准线性体、伯格斯和对数模型都是实验曲线的很好近似.为了进一步了解蠕变实验时间对模型参数的影响,研究了蠕变模型的预测功能.将实验蠕变曲线分成二部分,第一部分用于模型参数的反演,第二部分用于模型预测数据的检验.时间外延所得的模型的预测曲线都明显偏离了实测曲线,伯格斯和对数模型的预测曲线比实测曲线偏高,而标准线性体模型则偏低.根据不同时间的蠕变实验数据的比较和分析,认为实验时间对蠕变模型参数的反演有较为明显的影响,但只要对标准线性体模型作适当修正,引入与时间尺度有关的函数C(t),则该模型的预测能力就有较大的提高.

Comparison and Modification of Rock Creep Models

Creep experiment was processed for three kinds of rock samples under different constant stress. Model parameters were obtained by inversed creep curves with creep models, and it was found that the standard linear model, logarithmic function and Burgers model could almost perfectly fit any given creep data. In order to understand the effect of experimental time on the model parameters, the prediction capability of different models was studied. Whole experimental creep curves were divided into two parts, the first part was used to inverse the model parameters, while the second part was only used to check the prediction data produced by models. The prediction creep curves based on above-mentioned three models deviated from the experimental creep curves. The prediction creep curves of logarithmic function and Burgers model were greater, while the standard linear model was smaller than the experimental creep curve. According to the comparison and analysis of creep experimental data with different time, it was found that the experimental time had obviously effect on model parameters. As long as modifying the standard linear model and introducing a function related with time C(t), the prediction capability of standard linear model will be greatly improved.